Fuel tanks may experience increased pressure during certain operating conditions. The increased pressure may be caused by an increase in the temperature in a sealed fuel tank. The duration that a fuel tank is sealed may be increased in hybrid vehicles using both an electric motor and an internal combustion engine for motive power when compared to vehicles relying solely on internal combustion engines for motive power. The increase may be due, in part, to the sporadic use of the internal combustion engine in the hybrid vehicle. Consequently, the pressure in a fuel tank of a hybrid vehicle may reach levels that are many times greater than those experienced in systems where the fuel tank is routinely purged to the engine whenever necessary. In some circumstances the pressure in a fuel tank of a hybrid vehicle may be 15-20 times greater than the maximum values experienced by a fuel tank in a vehicle relying solely on an internal combustion engine for motive power.
Thicker fuel tanks have been used to withstand the increased pressure within the fuel tank, such as heavier gauge metal fuel tanks. However, the inventors herein have recognized various shortcomings of the above approach. For example, fuel tanks having increased wall thickness may not only increase vehicle costs, but may also increase the weight and size of the fuel tank. Moreover, the shape of the fuel tank housing may be selected based on the strength of the design rather than on the compactness of the design, thereby decreasing the compactness of the vehicle or the fuel tank's storage capacity. Consequently the vehicle's driving range may be decreased.
As such, various example systems and approaches are described herein. In one example, a distensible fuel tank included in a vehicle is provided. The distensible fuel tank includes a housing and a compliance structure coupled to the housing, the compliance structure including a base element coupled to a side of a structural element.
The compliance structure provides a desired amount of flexibility and strength to selected areas of the fuel tank. Additionally, structural characteristics of the compliance structure may be tuned to achieve specified fuel tank attributes. For instance, a thickness of the base element may not be equal to a thickness of the structural element, in one example. In this way, the compliance structure may be tuned for a variety of fuel tank geometries, and therefore may be used across a wide range of fuel tanks. As a result, the applicability of the fuel tank is increased, thereby reducing fuel tank production costs.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.